/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    ListNode* ReverseList(ListNode* head) {
       ListNode* cur = head;
       ListNode* next = nullptr;
       ListNode* pre = nullptr;
       while(cur!=nullptr)
       {
            
            next = cur->next;
            cur->next = pre;
            pre = cur;
            cur = next;
       }
       return pre;  
    }
};